允许在使用jQuery循环时切换项目

$('.project').each(function(index, element) {
  // 切换项目的操作
});

var currentProject = $('.project:first');
currentProject.addClass('active'); // 设置第一个项目为活动项目

$('.next-button').click(function() {
  var nextProject = currentProject.next('.project');
  if (nextProject.length === 0) {
    nextProject = $('.project:first');
  }
  
  currentProject.removeClass('active');
  nextProject.addClass('active');
  
  currentProject = nextProject;
});

var currentProject = $('.project:first');
currentProject.addClass('active'); // 设置第一个项目为活动项目

$('.next-button').click(function() {
  var nextProject = currentProject.next('.project');
  if (nextProject.length === 0) {
    nextProject = $('.project:first');
  }
  
  currentProject.fadeOut(function() {
    currentProject.removeClass('active');
    nextProject.addClass('active');
    nextProject.fadeIn();
    
    currentProject = nextProject;
  });
});